Water-heater construction.



L. 0. WADSWORTH.

WATER HEATER cowsmucnow.

APPLICATION FILED OCT. 3, 1911.

1,248,579. Patented Dec. 4, 1917.

4 SHEETS -SHEET F. L. 0. wauswomn.

WATER HEATER CONSTRUCTIQN. APPLICATION FILED ocr.a,1su.

Patented Dec. 4, 1917.

4 SHEETS-SHEET 2.

VWTNESSES' INVENTOR z aw wag wwfi F. L. O. WADSWORTHr WATER HEATER CONSTRUCTION. APPLICATWN FILED 0d. a, 19m.

1,248,579. Patented Dec. 4, 912

4 suinssuzn a.

Fig. 5

F. L. 0. WADSWORTH.

WATER HEATER CONSTRUCTION.

nrrucmou 'mcn OCT. 3, 1911.

Pat/entgd Dee. 4,1911v 6 3 0 Wm r 5 a M, 9 aw 65 3 s 99 m w 1 M9 .wa m

1 W 1/ a 71 5 a a R 1 '5 s vwm mu a F. I w I STA:

- OFFICE.

FRANK L. o. wmswom'n, or rrrmsnunqn, PENNSYLVmA.

, WIT-ER-BEAZQEB cons mucmoiv. 1 431579 Specification of Letters rum. Patented 17,

\vme'ln' a citizenacfthe United-States, resid= ing-utllfittsbm; h,-in the county of Allegheny 5 aml'Stwteof iennsylvamiu, lmve'invented certain mew and useful Improvements in WaterlHen-ter Qenstrueticns, of which the followingis specifieationh 'l hcfl'nvenzticn relates to impmvements in water hcuterscmd particularly to the unfo- Application mea'omber 3,1911. seua noteaam'ra.

ing m-stilflingbdxumund .gd's alve stem 1 I prcvidet e valve head 19 a central mechanism is.cfgeneralapplicction and' is motto hereggtrded as restricted to use in connectlpn jw-lth this particular type of heetcliflilh stmted. Y

lieierrihgfnow to Hi 3, in-cpnnectio! 1 L leading; toi-t he l mjer coil; B, 11nd2 isjthe hot Wate1, 0ut let leg d in g jnqm the .lov'ver inverted eo'il'; I), the ccntl ojllihg mechanism in the casing Krhei g- 1Iite1 p0sedbetween such mutie controlling;mechatnisnijfor goycrnmg ifglet-a-xjd n and sd'atmngdthet one the supply-cf ga -t'oithe burners. The in- 81118 ythei'fi rw llnte'd mexr'iberjs exposed vention hns for its objects; the provision of to the presenrec itheli quidffiewinjg into the imprcved mcuhsfor. regulatingthe supply heater,.wh lethe0therside is exposed to 15 of gas tmthebumers of u heaterby means the lu'essuyeotthe-]-1 q11id:flmyi g outof the of a-fcon'lbinecl water pressure .nnglthermoheater. fluid actuated member is a static eontrollingmechanism operati gnpon p eton 3 shdmg in cylinder 4, said cylinder the principle as. broadlydisclosed" in the emg pr v-m d wi h an external water BL'lHShi- PIWGHU to-Brait-hwaitc N0. 9598 of chamber hgt'v-l two fluid connections 6 20 1888. Several embodiments of theiny ntig :tnd; 7 ,the first 0 which is in ccmnninicaareillhstra-tcdeinmthe accol ljlpanyi g dvaw- Y-ll W t Suppl main: and ingg wh i other; of -whlch 1s-jeon ecte up through the Figures Land 2 are frontvu'ndgside eleva- T di t plpe Z xh \Yfl fi ii ticns respective-1y Ofthe: ordinary modern l 'm fl' f,' ,C)mmil{111ttesLnhth the left 25 instantaneousheater, suchhsgthahshown in han 1afil 9 xit l icxl l der "th ugh e the: patentto"Shook'=N0. 9v93;723, with1my P 5 QfllDJDlflllCgttjee Wlth the right improvement appliedtheretof Fig. 3, is a fl lnn fr H' G-SMI 1 11 11v trn11sVerse.sectionhnenlarged:schlethrcugh port- I I '1.' 0.. f! 1y kept 010 by my eontmlli11g -.1neel1anism Fig. 4 is a.sec- :1 vulvell 3km 3-w y b vf ny a 30 tinn"thmngh a :mdtlifihltype of:ccntmlli g P l Q1}Stl1uctmn,,;b!1t1lapmfemhly of t e Imovhnn ism ;1 Fig. is n-sectim1 through anl kll gl ltnga-fiyp y t ese ,ngs. bemg indis5 cther-ammlifietl igv pe of tmnt-rclli ug mecha- Outed y li fi ftfqqge .,nli eml= 1-3. The' nismilfigJG is mseet-ion:qthr ughemmther :stenn L of-th plfi s e hr gh a "modified t :pc 0t mmtrollin h v pmkmg box 15 011 the (JV Q 1 head 1 nd 35 mg. 7 is1a =tr tiu1 seeticn v ,1 v hthesteni-QB v 'nn'wli-fica-ticn ,mm theecjong s valveJQ can etmctimhb 1g. 1, n g mll secti on F fromthe inlet tlrlcu'ghhtill mmtheu mechfied;typehfihonl gaspipe I, which llingunechhnglsm. v liners. "VI-Th6 same "-I' gfirst 'tmthegenemlemmgementvf "1 8 un ons, pa ts th heateriparts:uQzShmvIi-hl nd llzedtq support 2, lzh-ist-he;;casji ,cqck;22, for nrewthe 13pm etely h E e as when the luweu revearseem" 'flhfifi' fl qH -J l Q -Im8l gas Valve (hflmbmfmily iiqttherg proyided with the hp njction 23 leading to V 'hscdtqighite the gas I erm ttent y fih mi h Ethe qutgmeticelly 1 controlled ed In unde toteliminu eethe n c ss ty o 106 recessed boss, which, when h valve Iiftfad-from its seat, engages with a washer on the valve box head and, thus seals the opening around the stem 18. The opening around the stem 14 is similarly sealed-when no water is flowingby a washer 21 secured to the cylinder head 16 and engaging with a central opposing boss on the piston member 3. The only leakage of water which can occur through the stufling box 15, takes placewhen the Water is flowi n and the piston member 3 is moved away rom the head 16. As this occurs only at infrequent intervals, the stuiling box 15 may be left quite loose, thus greatly reducing the friction on the stem 14; and avoiding any danger of the parts sticking in the opened position. In order to insure the seating of the piston boss against the washer 21 when. the parts are in closed position, a. certain amount of lost motion between the parts 3 and 19 is provided by slotting one end of the link 17, and a spring 19 is provided to hold. the valve 19 against its when the water actuated piston is in its normal left hand position.

The right hand end of the cylinder 4; also communicates through a port 24' with a rectangular water chamber 25 which is in communication through the elbow pipe 26, with the hot water outlet 2. Leading from this chamber is the thermostat chamber 27 in which is mounted the thermostat rod 28. This thermostat rod or tube is of zinc or copper or of some material having a greater eoefiicient of expansion than the material of I the chamber 27and is mounted on its upper end on a perforated collar 29, through which the hot water passes to the house supply pipe The lower end of the thermostat rod or tube 28 passes through a perforated guide collar. 31 and terminates in a knife edge which bears against the thermostat lever 32 which is mounted on posts 33 in the sides of the box 25. The long 'end of the lever 32 has a knife edge bearing on the second thermostat lever .Hwhich is mounted on an adjustable-point bearing 35, and the outer end of the second thermostat lever 34 bears upon, but is not connected with the stem 36 of the valve 12 already described. The thermostat lever system is held in position against expension of the thermostat rod. by means of a s ring 37, and the valve 12' is independent y held in positionby'a second spring 38, the spring 38, valve 12, and stem 36, being all readily removed by unscrewing the cap 39. The parts of the tliermostat inechaui-m can likewise be readily put in place or removed by taking off one side, 40, (Fig. 2)

of the box 25,-and the said parts may be adjustedin position from outside of the box by means of the adjustable screw support 35. If desired the upper endfof the thermostat chamber 27, may be connected with the T 8 by means of a -by-pass 4.1, in which case the T, '8, is provided with aspring controlled check valve (as described, for example, in Patent No. 993,722-i) of such construction that when no water is flowing into the inlet 1 from the pipe 7 the check valve will be open allowing a tree circulation of the water through the coils of the heater, the thermostat chamber 27 and the by-pass connection -ll; but when water is being drawn off through the iipe '30 and correspomlingly supplied throng i the pipe T, the check valve will be closed. shutting o'lf the counnunicm tion of the inlrt pipe 1 with the bypass 41.

The operation of the uut'oiuatir control mechanism just described is as follows: \Vhen the temperature of the waterin the heater is less than that at which the thermostat is set to operate the thermostat lever 3+ will be retracted out oi contact with the valve stem Sh ms shown in Fig. L;$ and the valve 12 will be closed, as already dcscribrd by the action oi the spring 33. it now the house outlet pipe 30 isopcn'ed, the pressure in the chamber 25 will be rrdlu'rd by the out How of the water below-the pressure of the iii-flowing water, this dillcroncc oi pressure being established by the resistance to the passage of the liquid through the heating coils. There will thus be set up a ditl'erence in pressure on the two sides of thc piston member 3, since the left hand cud oiithe cylinder 1H which this piston member moves is in direct connnunication through the port- 10, with the iii-flowing water, while the right hand endof the pistonchamber is in direct coma-iunication, through the small port 24 with the out-flowing liquid. in consequence oithis dillerrnce of pressure, the

piston member 3 will be moved to the right,

thus opening the gas valve 1!) and allowing the fuel to flow directly to themam heating burners where it will be ignited by the pilot light. \Vhen the flow of water through the heater is stopped, the pressure of the liquid will of course at once equalize itself again. since the difference of pressure at the inlet and at the outlet is kept up only by the flow of the li quidand the piston member 3 will be'restored to its initial'position, thus closthe out-flowing water rises above a certain predcterminedpoint for which the thermostat ma be set, the expansion of the thermostat ro or tube 28 will forcethe thermostat levers 32 and 34 dOwmmntil the-latter eon-v t'acts with the end of the'valve stem 36,. and

opens the valve 12, The openin of this valve. puts-both ends of the cylin ereiinto direct communication with the inflowing water, and equalizes the pressure on the two heater. These two pipes are connected, as

sides of the piston member 3 thereby allowing it to return to its first position and 010s ing the gas valve 19 as just described. In order that-this equalization of the pressure by the opnin sensibly fetal edby thepresence of the, port opening" 2 the latteris made of consider-- ably smaller area than the port'opening of the .valve 12. Th'eopening of the latter valve in the manner above-described has a further efi'ect of allowing a small amount of cold liquid to pass directly from the chamber 5 to the chamber'tlfi, and thence to the thermostat 'chamberQfiand the mixture of this cold water with thehot vwater in the thermostat chamber will aid in the quick reduction of the temperature of, the out-'-.

above described device may be made very sensitive, that is to say, the gas mgy be turned oil or on by the operation oft e device by variations of only a few degrees in temperature" of the out-flowing water. The

size of the port opening 24, and conse uent volumeof flow of the cold' water t erethrough when the valve 12 is open, may be re ulated if desiredby a plug valve 43.

he various parts of the mechanism dcscr'ibed may be conveniently supported in proper position one with respect to the other, and securedas a unit to the casing of the heater by means of a base plate 44.11:; clearly shown in Fig.2.

Construction of Fig. 4.

In. this construction QindiCateS as before the outlet from the coil or heating chamber; of the apparatus and 6 and 7 indicate pipes corresponding to the like numbored parts of Fig. 1, said pipcsleading respectively tothe main water supply. and tothe cold water inlet 1 at the top oi the.

in thcflpreviously described apparatus by a passage-way 5 which 'ronnnunicutes through a port'10' with the left hand side of a circular diaphragm chamber This diaphragm {chamber is divided into two two parts bythe diaphragm 51 which is preferably made of. thin corrugated metal, the outer edges of which are clamped'betwcen' the outwardly projecting flanges of of the valve 12 may not be said chamber, and the center of which is clamped to the stem 14'. A sprin 52 is interposed. between the center of t e diaphragm and the right hand wall of the diaphragm chamber, and serves to keep the diaphragm 51 normally deflected to the left asshown in Fig. 4. The right hand head of the (liuphragmchamber is bored to receive a phinger valve which is made in two parts 53 and 54. These parts are held in adjustable relation one with respect to the other by means of a screw 55'threaded into the lower part 54, and a spring 49 interposed between the head. of the screw 55 and the lower end of the part 53. Ready access to the interposed ad uBting nut is secured by providing an opening 56 in the wall of the'valve' box, this openin being closedby a cap 57. The upper art' 3 of the plunger valve is provided wit a port'58 whichis normally in communication with a ort 24 opening into the right hand end of t e main diaphragm chamber 50. The lower part 54 of the plunger valve is provided with a valve seat 12" which normally covers and closes the port 11' also leading into the right hand end of said diaphragm chamber. Communication. between the. space belowthe valve head 12 and the pas sage-way,5 is secured bymeans of a hole 59 throu h the flanged sides of the two halves o the diaphragm chamber 50. A spring 38' held in positionfby a cap 39 bears against the valve head 12 and keeps it normally placed tightly against. itslseat. The thermostat which I employ in this con-.

struction'is a liquid thermostat consisting ofa closed tube 60 filled preferably'w-ith some viscous liquid huving a high tempera ture coefficient of expansion, such for exam-v ple as glycerin or crude oil. Mounted concentrically in the lower end of this tube 60 isa smaller inner tube 61, and this tube is bored or reamed to receive :1 short metal plunger 62, which is made to fit the bore 1 1Q- of the tube 61 very accurately. The upper end "ofthis plunger-is pointed or coned and just above this conedend thereisa" short lengthof' leather or rubberlii which'herves as, a self-adjusting packing ring. 'lh-li ov-e this packing ring is a mass of liquid rner .icury or. fusible mani m which further serves to seal thev opening between {the plunger 62 and the liquidfilling the. tube 60. The upper end ofthe thermostat tube 129 is'closed by an adjustable screw- 65, the position of which serves to regulatethe position of the plunger 62 for any'giventem-peb ature .of the liquid in the tube. Below the plunger 62,- which, does not extend down to 126 I the lower end of the tube 61, there) is a second packing ring 66 of rubber or leatheri and below this again is a second --pl-nnger-67 which bears directly against the recessed,

end of'the upper part 53 of the plunger ,130

. connected to the diaphragm,

A stem'l' is and this stem operates a gas valve corresponding in structure to that in Fig. 3.

.The operation of this mechanism is as follows: 'When the water in the heater is at rest, audits temperature is less than that at which the thermostat set to act (by a joint adjustnumt of the screw (35 and the nut 55) the parts are in a position shown in Fig. 4. \V hen, under these conditions the flow of water through the heater is started, for example by opening a. faucet in the outlet pipe from the heater, the pressure in the thermostat chamber communicating" with the outlet pipe will be reduced below the pressure at the inlet by the resistance to the flow of water through the heating chamber, and this will in turn set. up a difference in pressure in the right and left hand ends of the diaphragm chamber 50, which c0mmunicatcs through the port openings 24 and 58 with the out-flowing water, and through the port opening 10 with the iii-flowing water. The difference in pressure will move the diaphragm 51 to the right against the pressure at the spring 52, and will open the gas valve which connected as before to the stem 14 of this diaphragm. \Vhen the flow of water is stopped the pressure on two sides of the diaphragm will be at once equalized, and the'diaphragm will be returned to the normal position shown in Fig; 4'by the reaction of the spring 52. If, while water flowing, the temperature rises above a certain predetermined pointdepe'ndent upon the setting of the thermostat parts the liquid in the thermostat tube 60 will expand thereby moving the valve part 53 and closing in part the port 24. Further expansion of the liquid will bring the part 53 into contact with the-screw 55 and the parts 53 and 54 will then move downwardly together-thereby closing still further the port 24' and opening the port 11. The opening of the port 11 allows the pressure on two sides of the diaphragm 51 to be equalized by the direct admission of'the in-flowing Water to the right hand diaphragm chainvalve previously described.

her and this equalization of pressure permits the diaphragm 51 to be returned to the normal position shown in. Fig. 4 in which the gas valve is closed and the fuel is shut off from the main burners. The closing in whole or in part of the port 24 by the first action of the valve part- 53 prevents, in this case, the flow of the cold water into the thermostat chamber. However, the parts 53 and 54may beso adjusted with relation to each other by means of the willmove-in unison with each other and leave the port 24- full open at the time that the port 11' is opened. I can therefore in this casr either prevent the cold water from mixing with screw 55 that they' the hot Water when the valvethe thermostat, or can perto occur to any extent that dons/traction 0 f Fig. 5;

In this construction 2 indicates as before the hot water outlet from the heater entering the thermostat chamber 27",*and 6 and 7 likewise indicate as before the cold Water connections leading from the water supply main to the cold water inlet 1 of the heater (see Figs. 1., 2 and 3). These pipes 6 and 7 2 communicate with each other through a chamber 5 and in this chamber there is or ranged a spring pressure check valve so mounted as to open with the flow of water into the heater. The left hand side of this check valve chamber communicates through the ports 71 and 10 with the 'left hand end of the cylinder 4 in which the fluid pressure operated. piston member 3 is located. v The right hand end ofthe valve chamber communicates through the ports 72 and 11 with the right hand end of the cylinder 4 A check valve 12 is mounted in the chamber between the port openings 10 and 11 this latter check valve being connected to a stem 36 leading through a stuiiing box 73 and provided at its outer end with an adjustable nut 74. The movement of the check valve 12 is in this construction etfected by a neg ativoly acting thermostat member which comprises a rod or tube 7 5 of zinc, copper or other material having a high 'coeflicient of expansion and the second rod or tube 76 of nickel, steel, porcelain or other material having a very small coefficient of expansion. The tube 75 is secured at its lower end, and the rod 76 secured to the tube 75 at its upper end and bears at its lower end upon theadjustable screw 77 which is mounted in the short arm of the thern'iostat lever 78. The longarm of this thermostat lever is forked to straddle the stem 36 and make engagement with the adjustable nut' 74, and the thermostat.- parts are. kept in operative engagement with one another-by means of a spring 79, the 'tension of which can be ad justed by a screw 80. \Vhen the tempera ture of the liquid in the thermostat chamber 27 rises, the tube 75 will expand more rapidly than the rod 76, andthat rod will in consequence of this be lifted, allowing the long arm of the thermostat lever to move to the left under the pressure of the spring 79. When the liquid in the thermostat reverse movement will occur.

chamber falls, the The stem 14 oil the fluid operated piston member 3 is connected as before by a link 17 with the the lower end of temperature of the piston 3 mdves to the right, the gasvalve will be opened, allowing the fuelto flow through the pipe G, the plug valve 22, and the pipe 'I to the main-burners of the heater.

It will be noted that the construction and operation of this gas valve like that of Fig. 3, is such that no packing box is re lured for the stem 18", 'for when the va ve is closed, the gas is shut elf vfrom the opening around the stem and when the valve is opened the washer on its right hand side is pulled tightly against the flanged head of v the-valve chamber and the openingaround the valve stem is thereby sealed. Similarly the opening around the stem 14 is sealed,

when no water is flowing, by the stem washer 81 which issecured atits outer edges to the central boss of the piston 3 and bears at its center against the opposing boss of the cylinderhead16 A spring 82 interposed between the washer sl and the'piston head .7 3 insures the sealing ofthe opening around the stem 14? independently of slightv variations in therelati've position s otthe'piirtsa connecting the piston 3 to the gas velvelB; and thus eliminating, in thiscase tlie-neces-g sity of providing forfany lost motion. in the link connection 17 for for-iproviding eny separate spring ;toact directly .on thef'ges ,T valve 19% Theivarious parts ofrthisaoon trolfmechanism'are all mountedjand proper adjnstablerelation one to the sother on a flanged frame oricastihg-SB bymeens. of bolts -a,nd,eap serews 84' and 85.f..j lathe-construction just describedigthedif ferences'o'f pressure'whicherefset'u {on'the' two sides of the;

ressure jope'rate piston 5 member 3 'are pro ucedzbyfthe action of tha spring check: valve 70.f-,1E,This velve pro- 'v ded with a small leakage 126M3 6. theta. vvhen the water is:not'fiow'iiig\through the ohainberb' the pressure'i'n the. chambers; on y the two sides of this valve, and consequently in the chambers iatthe twofends: {of the cylinder 4 will be equalized, iand piston meI'n -T her 3, end the gas velve'fl9 connected water vpast -;-thecheck valve against these thereto, will be held in the normelplosed. position shown in the figure, by the unbalanced pressure of the liqu'gd' against' the' headof the stout-14, and also if desired by anauxilia-ry spring-A2; When thevfiow of water is started, the check val-ve 7O willbe opened against thepressure exerted by the water on the stem OLth'ischecI valveiand by the restraining spring- '87; and the flow of the pressures will establish a corresponding dif? ference in pressure 1n the cha nbers on the two sides of sald valve and in the chambers at the two ends of the'cylinderfl' ,"thereby the main burners.

fmoving the" piston member 3* to the right V and openiugthe gas valve 19 p flout of water stops, the pressures Int/1168B When the various chambers will at once equalize themselves,'aml the piston member 3*,"and the gas valve- 19 connected therewith will move to the left shutting oil the fuel supply to If, while the water is still flowing. the temperature in the thermostat chamber rises to such a point as to allow the long end of thethermostatlever to come in contact with the nut 74, the check valve 12 will be openedby the pressure of. the spring 79, and.freeeonnnunication thus established between theport. 71, and the port 11 will'immcdiately equalize the pressures in the two ends of the cylinder 4", thereby closing the gas port as before. In order to avoid interference with this equaliis made considerably smaller in area than the opening throughethetvalve 1 2 and the port 11, endif desired, the stem-1 0i the checkvalve 12 inayialso be-provided-With a collar88 which. willgolose-l-the port-72 as the check valve=l2? opens,.-.; whenatheitem movedback out; of geontactiwithzthe nut 74 and the -valve;;12'= will be :closed-bythe' unbalalwedtpressuregofe the GViLtGB-flgfliIlSt: its 7 stem, and -the difference -of-- pressure estab-- lishedbythe flow of water through the main check valve-.70 will be Fence-more :set up on the two lsidestoft.thepistonunember 3 again 90 Siniilai l H nt islconstructionw es in the ones alrea describeds there is very .little frietional resistanee. the-movement of any n of the' operati .p ;-(beoeuse;either-packed pistons or diap rag'msererusedrandvbecausestulfing hoxes cenpb eliminated tor vleft very loose no' 'ffsticking? ofwthe. waterzxaetuated mem .e n tspen .hositioaiseve likel to OCQUI,UlllQSSuthQzflWhtfiEfihOllldaCOIltflll'l so Even in SHGhGttSESg-thfl access-of wdi-ment' to the-operatin gpartslnay be guarded ageinst by the use tsc'reensl89 and :91 covering the zation by the action of the port 72,' the latter Egrature falls, ;the thermostat=leven 7 8 will much sedimentgas, to -be.precticaHynnusable;'f.-

portopenings 71-, l'Q -and l1; These-screens 106 and the vnvepartsma 88,-etc. ,-are readily removed and replaced-shy- :taking -'outr the cap90.v,.

Gout motion 0)',Figs. 6- and-7.

In the construction: of the-preceding figures the control. mechanism has in-each case been placed I on thehlowempart-of the heater 1 shell .near the'ho't waterjeoiltletotermineli-bf' the heater coils. In the constructionashown.

in Figs, (i and/Z the- ,eontrol rnechenism is placed near the top of the. shellin'sclose proximity to thecold-weten in1et- :1',- In this case .the cold.watertpasses'fromthe pipe 6 connectedtofthewater main into a cham- 12o her 5 whichcomm-unicates through the port .10 with-the right hand. end .of the diaphragm chamber 50, andthence-directlyto the cold water inlet P. Thehotfiwaterl issuing from theheaterdoils.enters'thethermm stat chamber 27 at its lowerend, passesupwardly through said chamber :iiito thepipe' municates with the left'hand end of the dia phregm chamber 50 through a port open- 95, and thence into achainber'96 which coming 24:, and finally enters the house service pipe 30 The thermostat is of the same constructlon as that shown in F1 5, and hke that one is arranged to move he thermostat lever 97 positively to the left against the pressure of the springs 98 and 99 as the temperature falls. The diaphragm 51 is preferably of 'thin corrugated sheet metal clamped into position between the twoparts of the dia tihragm box, and is normally deflected to, the right by the pressure of the spring 100. By the center of the diaphragm there is fixed a disk. 101 which contains a small port 102, and which seats against the end of the plunger 103. The latter passes through a stalling box in the left hand wall its right hand side with the washer of the.

spring 08 and alsowith a threaded nut 10? which is held in place against the engaging surface of the thermostat lever bythe spring 00. The threaded nut I07 carries an adjustable scrcw 108, the head of which is opposite the end of a stem 100,-which passes through a stalling box in the left hand wall of the diaphragm chamber 50" and terminates opposite the port 24 m the cheek valve head 110.

The parts are normally adjusted as shown in the ligure, so that when the water is at rest and the temperature less than that at which the thermostat control may be set to act the check valve head 110 willbe out of contact with its sca(it being forced to the left. by the unbalanced prcssurc'of the water on the stem IOU-and the out 104 will be out of contact with the upper end of the thermostat l(!\'(l l 7. \Vith this adjustment the operation of the apparatus shown in Fig. 0 is as follows: \Vh'cn lhe water is drawn from the healer the pressure in the chamber SH? will be reduced below that in the chamber 5 by the rcsislancc to the [low of the ova-fer through the hcalcr coils, and the ports 10 and 2-! both being open. the diaphragm 51-- will be forced to the left carrying with it the plunger 1023 and the gas valve stem 10."), thus opening the gas valve 10 and admitting fuel to the main burners through the pipe I. As soon as the flow of water is stopped, the pressures in the chambers 5' and 90 are of course at once equalized and the diaphragm is returned to its normal right hand position by the joint act-ion of the springs 100 and 106, the gas valve 19 being simultaneously closed by'the latter. If, while the water is flowing the temperature rises above the point. for which the thermostat is-set, the resultant downward movement of the thermostatfeleinent 76 allows the'springs 98 and 99 to force 'the thermosl at lever 97 to the right-far enough to allow the port 2+ to be closed by the action of the parts 107, 108, 100 and 110. The moment that this port is closed the pressures on the two sides of the diaphragm 51 will begin to equalize by reason of the passage of the water from the one side of the diaphragm to the other through the small port 102. Thisequalization of pres sure' will allow the diaphragm 51 to be forced back to the right as before by the pressure of the'springs 100 and 106, and the gas valve 19" will be closed again. This movement of closure can be expedited and rendered more positive by adjusting the nut 104 so that the right hand movement of the thermostat lever' 97 will bring the end of said lever into engagement with the face of the nut and force the latter to the right. When the temperature falls again the con traction of th-cpo'si tivo member 75 of the thermostat will lift the negative member 70 and will force the thermostat lever 07 to the left, compressiin the springs 09 and 90, and successively or sm'iultmicously relieving the pressure on the nut'l04 and the check valve hcad 110. The latter will then be moved to the left by the unbalanced pressure. of tl1c water on the stem 100, and the port 24 again opened, thus puttingathe left hand side of the diaphragm chamber again in communi' cation with the chamber 00. If the water is still flowing through the heater, the opening of this port will reduce the pressure on the right hand side of the diaphragm 51 below that on the left hand side, because the water is withdrawn through the port 24- much more rapidly than it can be supplied through the small port opening 102. and the diaphragm will, in consequence of this. be once more moved to the left, again opening the gas valve 10.

- Fig. 7 illustrates a variation in the constrnction shown in Fig. 0.. .The only differcnce between these two constructions is that,

in the one shown in Fig. 7, the thcrn'iostat consists of a single positive element 28 which acts directly in its'cxpansion upon the thermostatlever moving the latter positively to the right and compressing the spring 110. The outer end of this thermostat other'end withtlie stem 105 of the gas va1ve; The 'n'ut'119 is prevented from rotation by means Ofa pin IQOengag'ing with the slot in the side ofthe thermostat lever chamber,

, 1s thesarhe' as that illustrated in Fig. 6,

save that the closing ofth'e plug check valve 118 and thepositive return of the plunger i 103; is 'efi'ected directly by the expansion of i the thermostat member 28; .While the reverse movement of g the parts isbrought about,-

When the temperature falls, by the pressure on the spring 116 Oonhtmlotio-rr of ig. 8

i In this" construction- 6 is the cold Water which cold water inlet pipe has leading to the upper coil of the heaterhnd corresponding to the pipe 7 in the construction of- Figs. 1, 2 and 3. The water ,valve casing 4 is provided with the pa'iriofports 10* and'j24? corresponding to the ports 10 and Q24 1 in the construction of Fig. 3; such ports being located-on opposite sides of the'piston 3. The port 2 1* com I, muni'cates' With-Ythethermostat casing 27 by means of the pipe 122, and the construe tion of the thermostat-parts 'and 76 correspond to that ofthe thermostat shown f inFig-;'5 the member (operating the pair oflevers 123 ,en'd124; pivoted as indicated in' "the idraw'ing, and so arranged that on the heatingflof the Water in the thermostat casing' and the expansion of the member 75;

the lower end of the lever'124 is caused to: move to: the left under the influence of the spring 125. ,The lower endof the thermostaticasing 27" communicates. with the lowereoils of-the heater by .means of a 45 p thronghthecasing 27%. heater via the pipe G? connection 2*", sothat on opening the. outlet from the casingQ-T the hot waterlfroni the heater flows through the connection 2* and G suppliedto the L and .1 passes through thega's "valve casing and past. the valve 1.9.

whic'h gas valveiis normally held closed by nieans gofftlie sparing 127,]. Thepiston neni her '3? is provided vvith a, transverse bar 128' 'rigidly'iif held in positionby means of. the studs 129,- andthi's loan l28'in-tnrn earries i, afrod or stein 130lyirig in] opposition to' the stem 1310f thefg a s'fvelve. Surrounding the stern 130 is e sleeve 132 carrying ateach end Y I a valve "seat, suchiseats 'j being-designated the; r ierenceenumemis 133i "and 134:.

, 1 u valve seats or disks 133.;R11d 134 areed'efited P to seat against the opposite ends e memberj 135 Such member being prolatter lying in aliueInentl-with the po' rt"2,4c-.

thepositionshownain the drawings, isi deing 27 andin' theflinlet piped, suchpres 124 acting under the 0. thu m v g; n e mit n "lhis condition is mftmtflmd until the' tem- 7 o Z l; l -.in such positlie apparatus,

.' Inally held in the relative position shown by means of the spring 139. The sleeve132' is adapted-to be moved. to the left in order to seat the disk 134 and unseat-the disk 133 by the tube 140 carrying at its front end a disk. 141 adapted'to be engaged ,by the-thermostat arm 124 :When the temperak ture-of the water in the heater rises above a predetermined point. The spring 142 servesto carry the tubelLO to theright when the lever 124:- is' permitted to 'move to i the right." V Assumingvthat the Water in theheater iscomparativelv eold and-the parts Fire in the position as shown in Fig. 8 the operationis as follows. On opening the outlet from the thermostat casing 27 Water flow-s into the heater through the pipes 6f andl". This operation gives a differential pressure on op osite sides. of the piston 3* :due' to the di erence in pressu-rein the thermostat cassure being communicated to theopposite sides of the piston via the pipe 122 and ports 24? and 138 on the one hand and: through the passage fl lBcand port lflfl onthe other hand,

inasmuch as theseatingof the disk 133 "upon its' seat prevents an equalization of pressure: through the annular space ou tside the sleeve f- 132. This differential pressure. of course c ajuses thepiston 3} to i-nove. to the right, thnso'pening'the gas valve 19* and permitting a flow of gas to the burners. If, during the outflow of watenfronihthe heater, the temperature of the -Watei-rises" above a predetermined point, 'thethermostat arm ipflnen'ceof the spring- I25 movesto theleft, thus carrying thetube 140 to'the left. This llcauses the seating of '5 thedisik 13% and 'thennseating' of the disk 133. @When the disk 133 is unseated;' the ressure onv the leftside of the piston 3" ay be communicated to the othersideof sidethe sleeve 132-, 137,'the seatingof the disk 134 -at this time preventing any reduetionof pressureonthe eft hand side of the iston. Thefpress'ure on thetwo sides of t e piston thnsibeing equalized,'it will return toitsiorigjml posithe stem' 13Q-to e left t e gas valve 19 tofclose.

.per'ature of the' 'watei'dmps snfliciently to permit; the. lever- 1-24; to more to therlght, at which time the d1$kf134 is unseated' and the disk 133 seatedQa'nd'the pressure infithe; casing is again unhalanced, causing thepis-jlflpf i the pistonfivia the annularpassage-way outi middle-ports 136 and ton to again open the gas valve. The check valve 8 serves to still further increase the difference in pressure upon the inlet and outlet pipes of the piston, when. the outlet from the heater is opened, although, if desired this check valve may be dispensed with, as the friction of .the water passing through the heater vrill always provid i a sul'licient difference of pressure between the ther mostat casing 27 and the inlet 6 to secure an. operation of the piston, it the piston made of, sufficient diameter, or it the pressure in the water supply duced very much below its usual value It will also be understood by those skilled in the art, that I may set up the operating differences in pressure on the two sides of the water actuated piston or diaphragm member in any other of the ways known to those skilled in the art, and that the necessary difference in water pressure potential may be secured by connections to separated points in the system different from the points illustrated. Other changes in mechanical detail not illustrated herein will readily suggest themselves to those skilled in the art.

Having thus described my invention and illustrated its use, what I claim as new and desire tosccure by Letters Patent is the fol-- .lowing: p

1. In an automatic water heater, a conduit through which the water passes to be -heated,.and comprising an inlet portion, an

outlet port-ion, and an intermediate heating portion, a burner for heating the said intermediate portion, a gas valve for controlling the supply of gas to the burner, a pair of pressure chambers lying outside'the conduit but connected respectively to the inlet and outlet portions whereby a differential pressure is secured in the chambers when the outlet from the heater isopen, means actuated by the differential pressure in the chambers for operating the gas valve. a passage-Way leading from the conduit bers, a thermostat governed by the heated water, and a valve in the said passageway operated by the thermostat.

In an automatic water heater, a conduit through which the Water passes to be heateth and comprising an inlet portion, an outlet portion, and an intermediate heating portion, a burner for hcating the said intermediate portion, afgas valve for controlling the supply of gas to the burner, a pair of pressure chamlwrslying outsidc the conduit. but connected lo separate portions of the conduit so farremo-vml from each other that lhe Friction ol the wa'tia' in the inlermmliate portion provides a substantialdifferential pressure in the two chambers when the outlet. is opened, means actuated by the diil'cicntial prcssure in the chambers main is not re "flow resisting member to one of the chamfor operating the gas valve, a passage-way leading from the conduit to one of the chant bars, a thermostat governed by the heated water, and a valve in the said passage-Way operated by the thermostat. v 3. In an automatic water heater, the combination of a water heating conduit having supply and discharge conneetlons, -a' flow resisting member located in said supply connection, a fuel supply valve, a pressure operated motor for governing said fuel valve, said motor having a piston movable'therein dividing said motor into two pressure chambers, one cation with said supply connection in advance of said resisting member, a restricted bypass about said. resisting member leading from said supply connection through the other pressure chamber to said connection, a valve governing said bypass and a thermostat governed by the heated water adapted to control said bypass valve.

4. In an automatic water heater, a combination with a water heating conduit, a located in the conduit, a fuel supply valve, a pressure operated 'motor for governing said fuel valve, said motor having a pressure actuated member dividing said motor into two pressure chambers, one of said chambers having constant communication with said. conduit in advance of the said flow resisting member, a by-pass around the resisting member landing from said conduit through the other pressure chamber to the conduit at a. point behind said resisting member, a valve governing said by-pass, and a thermostat governed by the heated water by-p'ass valve. In an automatic water heater, thecombination of a water heating conduit having supply and discharge connections, a How resisting member located, in said supply connection, a fuel supply valve, a pressure operated motor said motor havmg'a pressure actuated menn ber dividing said motor into two pressure chambers. one of said chambers having communii'eation with said supply connection in advance of said resisting member, a. by-pass to said resisting mcmber leading 't'ronrsaid of said chambers having conimuniv discharge.

for governing said fuel valve,

and adapted to control tlr' 

